A conventional multi chip package (MCP) includes a substrate, a first IC chip mounted on the substrate and a second IC chip mounted on the first IC chip. The substrate is provided with bonding posts thereon. The first and second IC chips and the bonding posts are wire bonded with thin bonding wires. The first and second IC chips are molded with a resin. Solder balls are arranged on the bottom surface of the substrate.
For wiring between the first and second IC chips, stud bumps may be used in order to improve bonding strength. However, when stud bumps are employed for a MCP, the productivity would be decreased. On the other hand, recently, a coated wire has been used for electrical connection among IC chips and a substrate so as to prevent the bonding wires from being contact with each other. However, both the stud bumps and coated wires cannot be used together. It is impossible to break the coating of the coated wires on the stud bumps, which are soft. Further, it is required to reduce mechanical stress under bonding pads, which are generated in a wire bonding process. Such mechanical stress is remarkable when coated wires are used.